Multiple choice Which of these are environmental pollutants and persistent organic pollutants? Persistent free radicals Nitrogen oxides Particulates Dioxins Toxic metals Reveal answer Fill a bubble to check yourself D Correct answer Explanation Dioxins and dioxin-like compounds (DLCs) are by-products of various industrial processes, and are commonly regarded as highly toxic compounds that are environmental pollutants and persistent organic pollutants (POPs).